The present invention relates to a steering angle sensor.
Japanese Patent Application Unexamined Publication No. P2001-505667 discloses a steering angle sensor including a gear (hereinafter referred to as a first gear) mounted on a steering shaft to make a unitary rotation therewith and two gears (hereinafter referred to as a second gear and a third gear) meshing with the first gear. The second and third gears are respectively equipped with magnets, and have numbers of teeth different from each other. The steering angle sensor can detect a rotation angle not less than 360 degrees on the basis of a difference between rotation angles of the second gear and the third gear which is generated because of the different numbers of teeth.